1. Field of the Invention
The present invention relates to a method for optimizing the utilization of crustaceans, e.g., whole lobsters through inclusion of under-utilized by-product components, which in combination with the intact lobster, provides for an enhancement of intrinsic appearance and edible proportion of the intact lobster. Particularly, this method has application among clawed lobsters of the Homaridae family, the clawless Spiny lobster and Rock lobster species of temperate and tropical origin and including species of the genera Panulirus, Jasus and Chelonectes. The method can also be applied to crab, and to lobster-like crustaceans, including some types of prawn, Nephrops norwegicus and freshwater crayfish species.
2. Description of the Prior Art
A traditional method for processing and packaging clawed lobsters of the Homaridae family consisted of cooking them whole, either by steam exposure or by hot water immersion, cooling the product and sealing them in plastic bags containing brine solution with subsequent freezing to render the lobster embedded in ice. Inherent to this traditional lobster frozen-in-brine product, a substantial degree of visceral staining of the edible meat components within the upper tail region was encountered. This was attributed, in part, to migration and rupture of the visceral hepatopancreatic fraction and intestinal tract contents during the preparative cooking procedure. Also inherent to this product were residual heavy-metal contaminants, which were predominately-located in the visceral fraction and which underwent migration to the edible body meat fraction as a result of cooking procedures. Thereby, the relative concentration of residual heavy-metal contaminants was enhanced in the edible meat fractions of the processed product.
Other traditional methods of processing intact lobsters consisted of freezing cooked lobsters, which were wrapped individually in wax paper in a master-box. Another common method involved the removal of the intact tail section of lobsters with subsequent individual quick-freezing, and packaging the tails through alignment into a box. In such products, the raw lobster material either in an intact form, or as tail sections was prone to problems of breakage due to the brittle nature of their shell material. Particularly, such problems were encountered during distribution and transportation procedures.
The extraction of meat from the body of hard-shelled crustaceans, e.g., crab, crayfish, lobster, and rock shrimp, as opposed to soft-shelled crustaceans, e.g., all shrimp species, other than rock shrimp, has proved to be very difficult, time consuming and expensive. Present day practices for obtaining the edible portions from such crustaceans, e.g., lobster, crab, crayfish and the like, involved a variety of mechanical, electrical and heat-treatments, which included subjecting the crustacea to a sawing action on the shells, a high or low electrical voltage through the shells, treatment with direct flame, immersion in boiling water or various chemical treatments, treatment with steam at atmospheric pressure or under high pressures in closed vessels. A myriad of other procedures were known which involved combinations of some or all of the foregoing methods. While some of the procedures may have experienced various degrees of success, most of the prior known procedures required hand labour to treat the individual fresh crustacea in order to remove the edible flesh.
Both raw and cooked hard-shell sections of processed lobsters have heretofore been subjected to many treating methods, for example, freezing intact for subsequent transformation by boiling for rendering extraction of flavour, or proteinaceous solubles and non-soluble components for further culinary applications. In addition, the head-shell material of either raw or cooked lobster was subjected to grinding reduction and mechanical meat removal procedures.
Various mechanical methods have been developed to remove either raw or cooked meat from mechanically-reduced head-shell material. In some techniques, physical separation of the meat from the shell was effected through the use of riffle tank particle separation methods. The shell effectively settled to the bottom, and the extracted meat was concentrated by water fluming and screen collection. A recognized impediment to this procedure was the loss of desirable and delicate flavour components attributed to the extensive washing procedures during separation.
In other traditional procedures, the cooked head-shells of lobster were subjected to mechanical grinding and reduction through use of perforated rotating drum technology. In this method, the edible meat, and visceral components contained within the head-shell component was separated from the shell fraction by the application of variable belt pressure against a perforated stainless steel drum. The size of the apertures in the drum provided for physical separation of the softer meat and visceral components from the hard brittle shell and cartilaginous skeletal material. Such products which were produced thereby were commonly recognized as "lobster mince" and found use as culinary ingredients within the food industry.
Many of the difficulties of removal of the meat stemmed from the physical structure of the hard crustacean shell, the manner in which the meat was stuck to the shell, the need to extract and maintain the meat in a minimum bacteriological manner, as well as the commercial desire to extract the meat in lump form rather than in many small pieces. The research, both by industry and universities, has been extensive and has resulted in various alleged improvements in the meat extraction processes.
Pre-treatment of the crustaceans by chemicals, the use of certain cooking conditions, the use of machines which squeezed the meat out, or which cored and centrifuged the meat out, or which air or water blasted the meat out, or which froze and exploded the meat out have been proposed and advanced with varying degrees of success.
Lobster, and limbs and claws thereof, have been efficiently used and formulated into limb-like or stick-like meat products or claw meat products. After removing the carapaces, gonads, branchiae and internals, the trunks were washed with water and ground-up. Then, the meat remaining in the trunks was recovered with a meat separator and was formulated into minced meat. This meat was further washed with water and the fibrous meat was taken therefrom and was formulated into flakes. Thus, various proteineous parts, which were mostly unutilized, including meat remaining in the carapace, the glands, branchiae and meat remaining in the trunks were not utilized, but was disposed of as such.
There are many patents which are directed to the processing of such crustaceans. Non-limiting examples include the following patents:
Sterling G. Harris, in U.S. Pat. No. 2,155,308, patented Apr. 18, 1939, and assigned to The Blue Channel Corporation, provided a procedure for canning crabs, which involved a preliminary heat-treatment in an aqueous fluid.
U.S. Pat. No. 2,501,655, patented Mar. 28, 1950 by W. M. Altenburg, disclosed a method for loosening lobster meat from its shell by heating the surface of the lobster meat adjacent to the shell (by boiling), and subsequently freezing the whole lobster.
U.S. Pat. No. 2,858,223, patented Oct. 28, 1958, by Sterling G. Harris, and assigned to The Blue Channel Corporation, provided a method for separating meat from crustacean shells, in which the meat was cooked and the shell was then impacted to release the meat.
U.S. Pat. No. 2,978,334, patented Apr. 4, 1961, by Lapeyre, and assigned to The Peelers Company, described a general procedure for extracting edible portions of crustaceans, e.g., lobsters, crabs, etc., from the skeletal portions thereof. This included the sequence of freezing and subjecting the frozen skeletal portions to vacuum, in order to effect a preliminary separation of the meat from the shell, and then removing the meat manually.
U.S. Pat. No. 3,513,071 patented May 19, 1970, by Gottlieb Bernhard Fehmerling, provided a method for the treatment of crustaceans, e.g., lobsters, crabs, etc. This included the use of a synergistic combination of enzymes that attacked the connective tissue which held the edible flesh to the shell.
Japanese Patent Number 46-10898, described a method wherein lobsters subjected to vacuum chamber conditions were exposed to protease enzymes in a temperature range of about 50.degree. C. to about 55.degree. C. for a period of time. By first vacuum eviscerating the crustaceans with subsequent release of vacuum and injection of steam, the raw meat which was attached to the shell of the lobster could more effectively be separated and be manually-removed.
U.S. Pat. No. 3,705,040, patented Dec. 5, 1972, by Peter W. Bynagte, and assigned to Westgate-California Foods, Inc., provided a procedure for extracting meat from crustaceans by dipping them in a particular pyrophosphate metaphosphate solution.
U.S. Pat. No. 3,773,962, patented Nov. 20, 1973, by Trelease et al, and assigned to A. Swift & Company, disclosed a method which included cleaning of the stomach and hind-gut of lobster by the use of vacuum to remove the contents of the stomach and visceral cavity.
U.S. Pat. No. 4,053,694, patented Oct. 18, 1977, by James E. Rutledge, provided a procedure for pre-treating hard-shelled crustaceans, e.g., lobsters, crabs, etc., to facilitate the removal of uncooked meat therefrom. This included the steps of freezing, and then thawing and extracting the uncooked meat from the shell by conventional manual, mechanical or centrifugal procedures.
U.S. Pat. No. 4,340,613, patented Jul. 20, 1982, by Michael P. Moore, described a method for cooking crustaceans, e.g., lobsters, crabs, shrimp, etc. This method included steam cooking with subsequent application of vacuum to extract the moisture from within the shell.
Other patents taught the production of seafood pastes. Non-limiting examples include the following:
U.S. Pat. No. 4,588,601, patented May 13, 1986, by T. Maruyama et al, and assigned to Kibun Company Limited, provided a method of producing a paste-product, from, e.g., various fish to provide pseudo lobster meat. This included dividing a fine-paste product, which had already been coagulated by heating, mixing the divided product with a protein mixture and then moulding the resulting mixture. The mixing and/or moulding procedure was carried out under reduced pressure and then the moulded product was heated.
U.S. Pat. No. 4,816,278, patented Mar. 28, 1989, by Sasamoto et al, and assigned to The Japanese Research and Development Association for Extrusion Cooking, Nippon Suisan Kabushiki Kaisha, Taiyo Fishery Co. Ltd., Kabushiki Kaisha Kobe Seikosho, Ajikan Co. Ltd., and Kogyo Co. Ltd., provided a method for processing and treating raw crustaceans, e.g., lobsters, crabs, mollusks and seaweed mixtures. This material was mixed together and an optional additive, e.g., soy protein, wheat flour or starch, which was added to the mixture by means of a twin-screw extruder.
U.S. Pat. No. 4,820,529, patented Apr. 11, 1989, by Y. Uchida et al, and assigned to Asahi Denka Kogyo Kabushiki Kaisha, provided a procedure for efficiently-utilizing the meat of crustaceans, e.g., lobster, or crab. This involved utilizing the meat remaining in the trunks and carapaces, by boiling and milling the crustaceans under sufficient conditions for inactivating the enzymes contained therein. Then, added proteolytic enzymes and/or microorganisms were allowed to act thereon.
U.S. Pat. No. 5,560,954, issued Oct. 1, 1996, to Gabriel Elbaz, described a method for preparing a culinary base product from the head-shell of lobster and other crustacean species. This involved a combination of oven heating the intact head-shell material, then subjecting it to mechanical-size-reduction with subsequent emulsification and addition of thickening agents for product stabilization. For the final product, this method provided for the use of both the carapace shell and the soft tissue components.
Thus, none of the conventional methods described above provided a procedure which combined the by-products and the inefficiently-utilized components of crustaceans, e.g., lobster processing into a procedure, which enhanced the convenience of the intact product and overcame the limitations of the prior art.